The present invention is concerned with a sustained release pesticidal composition,, and in particular is concerned with a sustained release pesticidal composition which contains a pesticide; a binding agent for the pesticide; and a matrix of a water-insoluble but water-swellable hydrophilic polymer. The present invention is also concerned with methods for preparing the pesticidal compositions.
It has previously been suggested to incorporate pesticides into hydrophilic polymers to provide sustained release of the pesticide. However, the particular pesticides which have to date been satisfactorily employed in such a sustained release mechanism are very limited since not every combination of a pesticide and any type of hydrophilic polymer provides a suitable slow release mechanism. Furthermore, such systems are not very susceptible to tailoring the release for a particular application. That is, the slowing down or speeding up of a release system is not readily accomplished. In addition, many prior suggested sustained release pesticidal compositions require relatively large quantities of synthetic materials.
Accordingly, it is an object of the present invention to make it possible to provide sustained release pesticidal compositions which are applicable for a large variety of pesticidal agents. Another object of the present invention is to provide a means by which it is possible to selectively alter the release characteristics for a particular application. A further object of the present invention is a reduction in the quantity of synthetic materials without a concomitant reduction in the release characteristics of the pesticidal compositions.